My kitty will attempt to cover up her vomit, including hair balls, but what she ends up doing is just scratching at the carpet. She will cast her eyes up at me, as if to say, "I'm sorry. I didn't mean to make a mess." Then she'll stand there and watch guiltily as I clean it up. I always try to give her as much comfort as I can, because I know she's not being deliberately messy. On the other hand, my mom had a cat years ago, who would purposefully heave for ten minutes until he finally made something come up. He would always do this while standing on the belongings or bed of whomever he was currently mad at. It was so obviously an act of retaliation that we finally had to banish that cat from all of the bedrooms. After that, he would throw up on the couch or living room chairs. He was so deliberate about it that we knew he wasn't really sick, but just angry about something. He was an odd cat anyway, who suffered from Pica as a kitten and would eat anything, including wood and paint. In his elderly years he developed seizures from the lead poisoning, but during the in-between years we had to clean up a lot of retaliatory vomit from that cat. I've never known a cat since then who threw up deliberately, but every cat I've had has always tried to clean up or hide the mess after. Some cats will even attempt to re-eat the vomit, something that dogs are well-known for doing. I try to stop cats from doing that if I can catch them in time. If possible, I like to clean up the vomit right away, usually I'm going for the cleaning materials as soon as I hear retching sounds. That way, the mess doesn't get eaten again, and it also doesn't dry right into the carpeting. I have never had a cat who tried to hide the mess with his toys, but I have had a few messes that landed directly ON the cat toys. Basically, it lands wherever the cat happens to be when he gets sick, and then he'll walk a few paces away and do it again. That's the traditional cat technique. They don't like to throw up in the same place twice, apparently.
